Initial implementation for modularized smartdevice (#757)

The initial steps to modularize the smartdevice. Modules are initialized based on the component negotiation, and each module can indicate which features it supports and which queries should be run during the update cycle.

kasa/smart/modules/timemodule.py

@@ -0,0 +1,52 @@
+"""Implementation of time module."""
+from datetime import datetime, timedelta, timezone
+from time import mktime
+from typing import TYPE_CHECKING, cast
+
+from ...feature import Feature
+from ..smartmodule import SmartModule
+
+if TYPE_CHECKING:
+    from ..smartdevice import SmartDevice
+
+
+class TimeModule(SmartModule):
+    """Implementation of device_local_time."""
+
+    REQUIRED_COMPONENT = "time"
+    QUERY_GETTER_NAME = "get_device_time"
+
+    def __init__(self, device: "SmartDevice", module: str):
+        super().__init__(device, module)
+
+        self._add_feature(
+            Feature(
+                device=device,
+                name="Time",
+                attribute_getter="time",
+                container=self,
+            )
+        )
+
+    @property
+    def time(self) -> datetime:
+        """Return device's current datetime."""
+        td = timedelta(minutes=cast(float, self.data.get("time_diff")))
+        if self.data.get("region"):
+            tz = timezone(td, str(self.data.get("region")))
+        else:
+            # in case the device returns a blank region this will result in the
+            # tzname being a UTC offset
+            tz = timezone(td)
+        return datetime.fromtimestamp(
+            cast(float, self.data.get("timestamp")),
+            tz=tz,
+        )
+
+    async def set_time(self, dt: datetime):
+        """Set device time."""
+        unixtime = mktime(dt.timetuple())
+        return await self.call(
+            "set_device_time",
+            {"timestamp": unixtime, "time_diff": dt.utcoffset(), "region": dt.tzname()},
+        )